| Summary: | 碩士 === 國立成功大學 === 工程科學系專班 === 98 === The manufacturing of an IC electronic device goes through various processes from wafer fabrication to assembly, experiencing different levels of tresses and risks. The final test validates the functionality of each DUT (Device Under Test) in the package form before its shipment.
BGA sockets with spring pins acting as an interface between the load board and the DUT during testing are high-price consumables. The quality of sockets determines the yield of the IC testing. However, the performance of a socket decreases with the increasing number of touches and can cost a lot if it is replaced wrongly.
Therefore, to get the balance between quality and cost of sockets, a counter embedded in the BGA socket is used to record the number of touches between the pins and solder balls in this study. Thus, wear of the four contact points of the spring pin to the solder ball can be monitored to see its effect on the contact resistance real time.
The results show that there is variation in contact resistance even in new pins. Thus, the time of replacing individual pins due to wear varies. The increase in contact resistance is mainly caused by wear and arcing as the number of touches increase. On the other hand, the spring force of individual pins is not significantly affected by the number of touches; namely, the spring force is not a good indicator of pin wearing. A meter system is designed and deployed in this study to monitor the increase in contact resistance so that the socket quality can be assured.
Keywords: Device testing, IC socket, Spring pin, Contact resistance
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